Daily Record Highs are Dramatically Outpacing Daily Record Lows

Dec 6, 2017

By Climate Central

Daily record highs are vastly outpacing daily record lows in the U.S. We will always have warm years and cold years, but in a world without global warming, those warm and cold years would balance over time. However, that’s not what we are seeing. According to the 2017 U.S. Climate Science Special Report, after a rigorous reanalysis of GHCN stations back to 1930, 15 of the last 20 years had more daily record highs than daily record lows. The number of daily record highs outpaced daily record lows more than 4 to 1 in 1998, 2012, and 2016.

A first look at the data from NOAA/NCEI indicates that 2017 continues the warming trend, as daily record highs are beating daily record lows by a 3.5-to-1 margin so far. Below are some preliminary 2017 stats through the end of November. Visit the NOAA Daily Weather Records tool to get the daily updates on these numbers:

Monthly record highs have outnumbered monthly record lows at a rate of 9.7 to 1

All-time record highs have outnumbered all-time record lows 8.7 to 1

Record high minimum temperatures have outnumbered record low minimums 4.6 to 1

The lack of record cold indicates that cold snaps are becoming less intense. On average, longer summers are pushing spring earlier and fall later into the year. This extends the frost-free season, allowing for more days with pollen and triggering asthma for those with allergies. As a result, the shorter winter also means that more insects can survive, which can damage crops.

Winter is the fastest warming season in most of the country generally from the Front Range of the Rockies to the East Coast. The greatest warming along the northern states emphasizes a general rule of climate change — cold areas and seasons warm faster than areas and seasons that are already warm. But there are a few exceptions. Fall is warming the

A winter heat wave is spreading inland from the West Coast and could bring unseasonable warmth spanning from coast-to-coast by the weekend. Southern California is on track to continue setting hot temperature records, Phoenix will have its earliest first 90°F day of the year, and parts of the South could see temperatures 20°-30°F above normal

Despite the current cold snap, 2016 is still on pace to be the second warmest year on record in the U.S. This temperature imbalance is illustrated in the ratio of record highs to record lows. In a stable climate, the long-term ratio should be in balance, or around 1-to-1, but that has not been the case for a long time. In 2016, the number of

In a mark of just how warm 2016 has been in the U.S., record high temperatures are outpacing record lows by more than 5-to-1, according to data from the National Oceanic and Atmospheric Administration. This trend is one of the hallmarks of climate change, and is expected to become even more lopsided in favor of record heat if greenhouse gas